sdm710-common: audio: Enable AOSP bluetooth audio HAL v2

Author: Cheney Ni <cheneyni@google.com>
Date:   Mon, 18 Feb 2019 14:34:20 +0800

    sdm710-common: audio: Support A2DP offload for Bluetooth Audio HAL
 V2

    Bug: 124277691
    Bug: 124014853
    Test: manual with BluetoothAudioHAL enabled / disabled
    Change-Id: Ibc86687a6a6c2f0767a213ccd408e7bb5de98985

Change-Id: I4d12752ae5fb2829d6612647c8740c84967f5434